This invention relates to a vibratory conveyor and more particularly to a vibratory conveyor which permits movement of product in the normal direction of flow for such a conveyor, and also permits discharge of product through a side aperture of the conveyor, moving the product transversely to the normal direction of flow.
Vibratory conveyors are generally used industrially to move fragile, small or lightweight articles from one point to another. An example of a distribution system is that normally used in the snack food and crisp industries where a series of main line conveyors transport products to crossfeeder conveyors set at right angles to the main line conveyors, each crossfeeder conveyor supplying a packaging machine. The interface between the main line conveyors and crossfeeder conveyors needs to be arranged so that product can either be conveyed to the main line conveyor, or to the crossfeeder conveyor, or to both conveyors simultaneously.
One known type of main conveyor is shown diagrammatically in FIGS. 1 and 2a. The type of conveyor comprises a frame 11, a tray 12 for receiving product, the tray being mounted to the frame by resilient means comprising at least one flexure 13 inclined to the vertical, and a drive system (not shown) to vibrate the tray within the path defined by the flexure. The flexures are typically fibre glass leaf springs, and the consequences of the arrangement is that product is thrown forward in the direction of conveyance with each cycle of the drive system. The springs are arranged so that product is conveyed along the tray, i.e. the direction of vibration is along the tray's length.
The crossfeeders are generally arranged so that their upstream ends are located at the downstream ends of the main line conveyors. If the crossfeeder intrudes into the main line, then it is necessary for product to pass across the crossfeeder from one main line conveyor to the next, except in the case of the last crossfeeder or in a case where no product is required downstream of a particular crossfeeder. For this purpose either the crossfeeder must be capable of conveying product transversely with respect to its length, as well as along its length, or one has to rely on the product being pushed across the crossfeeder by the force exerted on it by product which is still on the main line conveyor on the upstream side. Alternatively, the main conveyors may be butted against one another with side discharge apertures onto the crossfeeders. With present equipment, feeding onto a crossfeeder is most normally achieved either with a diverter which encourages product towards the aperture or by inclining the main conveyor (as in GB-A-2101950) so that product falls through the aperture. Both these arrangements require increased mechanical complexity and the inclined conveyor system results in increased grading by size of the particles of product.